Gu Xuehong

相转化凝固浴对Al 2 O 3 中空纤维多孔载体微观结构的影响

采用相转化法制备出具有非对称结构的Al 2 O 3 中空纤维多孔载体, 研究了不同浓度乙醇/水溶液为内、外凝固浴条件下中空纤维载体的微观结构和性能的变化。研究结果显示, 采用水为内凝固浴, 随着外凝固浴中乙醇含量的提高, 所制备的载体内层指状孔逐渐向外延伸且孔道变大, 其三点弯曲强度呈现先增大再减小的趋势, 纯水通量及N 2 渗透性先减小再增大; 内凝固浴对中空纤维多孔载体的结构也会产生一定的影响。以无水乙醇作为内凝固浴、水为外凝固浴所制备的Al 2 O 3 中空纤维载体, 其内层为海绵层, 外层为指状孔, 其N 2 渗透性约为6.85×10 -5 mol/(s·m 2 ·Pa), 纯水通量约为4.5 m 3 /(m 2 ·h)。采用相转化法制备出具有非对称结构的Al 2 O 3 中空纤维多孔载体, 研究了不同浓度乙醇/水溶液为内、外凝固浴条件下中空纤维载体的微观结构和性能的变化。研究结果显示, 采用水为内凝固浴, 随着外凝固浴中乙醇含量的提高, 所制备的载体内层指状孔逐渐向外延伸且孔道变大, 其三点弯曲强度呈现先增大再减小的趋势, 纯水通量及N 2 渗透性先减小再增大; 内凝固浴对中空纤维多孔载体的结构也会产生一定的影响。以无水乙醇作为内凝固浴、水为外凝固浴所制备的Al 2 O 3 中空纤维载体, 其内层为海绵层, 外层为指状孔, 其N 2 渗透性约为6.85×10 -5 mol/(s·m 2 ·Pa), 纯水通量约为4.5 m 3 /(m 2 ·h)。

Preferential oxidation of CO in a hydrogen-rich gas through Au/NaY catalytic membranes

Abstract This paper describes novel Au/NaY catalytic membranes for preferential oxidation of CO (CO-PROX) in an H 2 -rich gas. NaY zeolite membranes with a high CO 2 /N 2 separation factor were loaded with nanosized Au particles using an ion-exchanged method. X-ray diffraction analyses showed that the structure of the NaY zeolite was not damaged by the ion exchange process. CO-PROX experiments showed that the catalytic membranes had excellent catalytic performance for selective oxidation of CO. The CO/H 2 molar ratio on the permeate side decreased with increasing operating temperature in the range of 80–200°C. At 200°C, almost no CO was detected from the permeate stream of a catalytic membrane with the feed containing 0.67% CO, 1.33% O 2 , 32.67% H 2 , and He in balance. Thus, these Au/NaY catalytic membranes show a promise for CO removal from hydrogen fuels.